PROVERA® (medroxyprogesterone acetate tablets, USP) WARNINGS CARDIOVASCULAR AND OTHER RISKS Estrogens with progestins should not be used for the prevention of cardiovascular disease or dementia. (See CLINICAL STUDIES and WARNINGS, Cardiovascular disorders and Dementia.) The Women’s Health Initiative (WHI) estrogen plus progestin substudy reported increased risks of myocardial infarction, stroke, invasive breast cancer, pulmonary emboli, and deep vein thrombosis (DVT) in postmenopausal women (50 to 79 years of age) during 5.6 years of treatment with daily oral conjugated estrogens (CE 0.625 mg) combined with medroxyprogesterone acetate (MPA 2.5 mg) relative to placebo. (See CLINICAL STUDIES and WARNINGS, Cardiovascular disorders and Malignant neoplasms, Breast cancer.) The Women's Health Initiative Memory Study (WHIMS), a substudy of the WHI study, reported increased risk of developing probable dementia in postmenopausal women 65 years of age or older during 4 years of treatment with daily CE 0.625 mg combined with MPA 2.5 mg, relative to placebo. It is unknown whether this finding applies to younger postmenopausal women. (See CLINICAL STUDIES and WARNINGS, Dementia, and PRECAUTIONS, Geriatric Use.) In the absence of comparable data, these risks should be assumed to be similar for other doses of CE and MPA and other combinations and dosage forms of estrogens and progestins. Because of these risks, estrogens with or without progestins should be prescribed at the lowest effective doses and for the shortest duration consistent with treatment goals and risks for the individual woman. DESCRIPTION PROVERA® tablets contain medroxyprogesterone acetate, which is a derivative of progesterone. It is a white to off-white, odorless crystalline powder, stable in air, melting between 200 and 210°C. It is freely soluble in chloroform, soluble in acetone and in dioxane, sparingly soluble in alcohol and in methanol, slightly soluble in ether, and insoluble in water. The chemical name for medroxyprogesterone acetate is pregn-4-ene-3, 20-dione, 17-(acetyloxy)-6-methyl-, (6α)-. The structural formula is: Each PROVERA tablet for oral administration contains 2.5 mg, 5 mg or 10 mg of medroxyprogesterone acetate and the following inactive ingredients: calcium stearate, corn starch, lactose, mineral oil, sorbic acid, sucrose, and talc. The 2.5 mg tablet contains FD&C Yellow No. 6. CLINICAL PHARMACOLOGY Medroxyprogesterone acetate (MPA) administered orally or parenterally in the recommended doses to women with adequate endogenous estrogen, transforms proliferative into secretory endometrium. Androgenic and anabolic effects have been noted, but the drug is apparently devoid of significant estrogenic activity. While parenterally administered MPA inhibits gonadotropin production, which in turn prevents follicular maturation and ovulation, available data indicate that this does not occur when the usually recommended oral dosage is given as single daily doses. Pharmacokinetics The pharmacokinetics of MPA were determined in 20 postmenopausal women following a single-dose administration of eight PROVERA 2.5 mg tablets or a single administration of two PROVERA 10 mg tablets under fasting conditions. In another study, the steady- state pharmacokinetics of MPA were determined under fasting conditions in 30 postmenopausal women following daily administration of one PROVERA 10 mg tablet for 7 days. In both studies, MPA was quantified in serum using a validated gas chromatography-mass spectrometry (GC-MS) method. Estimates of the pharmacokinetic parameters of MPA after single and multiple doses of PROVERA tablets were highly variable and are summarized in Table 1. Table 1. Mean (SD) Pharmacokinetic Parameters for Medroxyprogesterone Acetate (MPA) Tablet C max T max Auc 0-(∞) t 1/2 Vd/f CL/f Strength (ng/mL) (h) (ng·h/mL) (h) (L) (mL/min) Single Dose 2 × 10 mg 1.01 (0.599) 2.65 (1.41) 6.95 (3.39) 12.1 (3.49) 78024 64110 (47220) (42662) 8 × 2.5 mg 0.805 (0.413) 2.22 (1.39) 5.62 (2.79) 11.6 (2.81) 62748 74123 (40146) (35126) Multiple Dose 10 mg * 0.71 (0.35) 2.83 (1.83) 6.01 (3.16) 16.6 (15.0) 40564 41963 (38256) (38402) *Following Day 7 dose A. Absorption: No specific investigation on the absolute bioavailability of MPA in humans has been conducted. MPA is rapidly absorbed from the gastrointestinal tract, and maximum MPA concentrations are obtained between 2 to 4 hours after oral administration. Administration of PROVERA with food increases the bioavailability of MPA. A 10 mg dose of PROVERA, taken immediately before or after a meal, increased MPA Cmax (50 to 70%) and AUC (18 to 33%). The half-life of MPA was not changed with food. B. Distribution: MPA is approximately 90% protein bound, primarily to albumin; no MPA binding occurs with sex hormone binding globulin. C. Metabolism: Following oral dosing, MPA is extensively metabolized in the liver via hydroxylation, with subsequent conjugation and elimination in the urine. D. Excretion: Most MPA metabolites are excreted in the urine as glucuronide conjugates with only minor amounts excreted as sulfates. E. Special Populations Renal Insufficiency The pharmacokinetics of MPA in patients with varying degrees of renal insufficiency have not been investigated. Hepatic Insufficiency MPA is almost exclusively eliminated via hepatic metabolism. In 14 patients with advanced liver disease, MPA disposition was significantly altered (reduced elimination). In patients with fatty liver, the mean percent dose excreted in the 24-hour urine as intact MPA after a 10 mg or 100 mg dose was 7.3% and 6.4%, respectively. F. Drug Interactions No formal pharmacokinetic drug interaction studies have been conducted with PROVERA CLINICAL STUDIES Effects on the Endometrium In a 3-year, double-blind, placebo-controlled study of 356 nonhysterectomized, postmenopausal women between 45 and 64 years of age randomized to receive placebo (n=119), 0.625 mg conjugated estrogen only (n=119), or 0.625 mg conjugated estrogen plus cyclic PROVERA (n=118), results showed a reduced risk of endometrial hyperplasia in the treatment group receiving 10 mg PROVERA plus 0.625 mg conjugated estrogens compared to the group receiving 0.625 mg conjugated estrogens only. See Table 2. Table 2. Number (%) of Endometrial Biopsy Changes Since Baseline After 3 Years of Treatment * Histological Placebo CEE † PROVERA ‡ Results (n=119) (n=119) + CEE (n=118) Normal/No hyperplasia (%) 116 (97) 45 (38) 112 (95) Simple (cystic) hyperplasia (%) 1 (1) 33 (28) 4 (3) Complex (adenomatous) hyperplasia (%) 1 (1) 27 (22) 2 (2) Atypia (%) 0 14 (12) 0 Adenocarcinoma (%) 1 (1) 0 0 *Includes most extreme abnormal result † CEE = conjugated equine estrogens 0.625 mg/day ‡ PROVERA = medroxyprogesterone acetate tablets 10 mg/day for 12 days In a second 1-year study, 832 postmenopausal women between 45 and 65 years of age were treated with daily 0.625 mg conjugated estrogen (days 1-28), plus either 5 mg cyclic PROVERA or 10 mg cyclic PROVERA (days 15-28), or daily 0.625 mg conjugated estrogen only. The treatment groups receiving 5 or 10 mg cyclic PROVERA (days 15- 28) plus daily conjugated estrogens showed a significantly lower rate of hyperplasia as compared to the conjugated estrogens only group. See Table 3. Table 3. Number (%) of Women with Endometrial Hyperplasia at 1 Year CEE * MPA † + CEE * (n=283) MPA 5 mg MPA 10 mg (n=277) (n=272) Cystic hyperplasia (%) 55 (19) 3 (1) 0 Adenomatous hyperplasia without atypia 2 (1) 0 0 * CEE = conjugated equine estrogen 0.625 mg every day of a 28-day cycle. † Cyclic medroxyprogesterone acetate on days 15 to 28 Women’s Health Initiative Studies The Women’s Health Initiative (WHI) enrolled approximately 27,000 predominantly healthy postmenopausal women in two substudies to assess the risks and benefits of either the use of daily oral conjugated estrogens (CE 0.625 mg) alone or in combination with medroxyprogesterone acetate (MPA 2.5 mg) compared to placebo in the prevention of certain chronic diseases. The primary endpoint was the incidence of coronary heart disease (CHD) (nonfatal myocardial infarction (MI), silent MI and CHD death), with invasive breast cancer as the primary adverse outcome studied. A "global index" included the earliest occurrence of CHD, invasive breast cancer, stroke, pulmonary embolism (PE), endometrial cancer (only in the CE/MPA substudy), colorectal cancer, hip fracture, or death due to other cause. The study did not evaluate the effects of CE or CE/MPA on menopausal symptoms. The estrogen plus progestin substudy was stopped early. According to the predefined stopping rule, after an average follow-up of 5.2 years of treatment, the increased risk of breast cancer and cardiovascular events exceeded the specified benefits included in the “global index.” The absolute excess risk of events included in the “global index” was 19 per 10,000 women-years (relative risk [RR] 1.15, 95 percent, nominal confidence interval [nCI], 1.03-1.28). For those outcomes included in the WHI “global index” that reached statistical significance after 5.6 years of follow-up, the absolute excess risks per 10,000 women- years in the group treated with CE/MPA were 6 more CHD events, 7 more strokes, 10 more PEs, and 8 more invasive breast cancers, while the absolute risk reduction per 10,000 women-years were 7 fewer colorectal cancers and 5 fewer hip fractures. (See BOXED WARNINGS, WARNINGS and PRECAUTIONS.) Results of the CE/MPA substudy which included 16,608 women (average age of 63 years, range 50 to 79; 83.9 percent White, 6.8 percent Black, 5.4 percent Hispanic,